Ophthalmic bridge lock



June 25, 1946. R. MALCOM 2,402,827

OPHTHALMIC BRIDGE LOCK Filed July 28, 1943 Roberfjf alcom,

Patented June 25, 1946 OPHTHALMIC BRIDGE LOCK Robert Malcom, Chicago, Ill., assignor to Chicago Eye Shield Company, a corporation of Illinois Application July 28, 1943, Serial No. 496,487

. 4 Claims. 1

This invention relates to means for locking and permitting adjustment of bridge members connecting the eyecups or other lens holders of goggles and other ophthalmic mountings.

My Patent No. 2,276,222, Ophthalmic device, March 10, 1942, discloses eflicient and satisfactory means for locking and permitting adjust ment of goggle-cup spacing or bridge members. The. bridge lock disclosed in that patent includes a .detent 11, which is movable in the wall of an eyecup to and from lock position with respect to the bridge member. As seen in Fig. 3, the detent is loose in the bore provided therefor and is retained therein by a bushing 2i, and it is retained by a spring 23 as seen in Figs. 4 and 5.

The present invention provides a bridge-lock detent of novel form that is self-retentive in the bore.

The invention is exemplified herein in association with goggles, and for convenience and brevity the lens holders are referred to as eyecups, but it is to be understood that the disclosure made and terms used are intended to denote also comparable parts of any ophthalmic mounting to which the invention is applicable, and that it is not limited to mountings of the goggle type. Like reference-characters refer to corresponding parts in the views of the drawing, of which- Fig. 1 is a view of a pair of gog les, some of the parts being shown in section;

Fig. 2 is an enlarged fragmentary front View of an eyecup;

. Fig. 3 is a section on line 3-3, Fig. 2;

Fig. 4 is an elevation of the lock detent;

Fig. 5 is a section on line 55, Fig. 4;

Fig. 6 illustrates a piece of stock from which the detents may be made.

Goggles of a type shown for purpose of explanation include eyecups 6 with rigid side walls 1 shaped at their rear edges to conform to average facial contours adjacent to the eyes. Each eyecup has at its annular front edge a lens 8 normally held tight thereagainst by a loosenable member such as, for example. an interiorly threaded retaining ring 9 screwed onto an exteriorly threaded portion of the eyecup and having a flange overlapping the lens. The eyecups may be of conventional form, except as later described, and they may have parts II] for connection with a headband (not shown) as is common in the art. The eyecups advantageously may be made of moldable light and strong material capable of withstanding hard usage when worn and handled by workmen.

In order to permit an elongated bridge mem- 2 her to move transversely through the wall of one or both of a pair of eyecups for adjusting the length of the bridge between the cups, the side wall of one or both of the cups is perforated in its nasal side by a hole orpassage I l disposed substantiallyperpendicular to the cup axis and circular in cross section and large enough to permit abutment parts of the bridge to have longitudinal movements therein.

A bore or passage l2, of uniform diameter from end to end, extends entirely within the eyecup wall from the front edge of the eyecup to the passage II with which it intersects. The bore is substantially parallel to the axis of the eyecup and thus substantially perpendicular to the passage I I. It is to accommodate a lock part later described. 1

A bridge member l3, for connecting two eyecups, is elongated and usually flexible, and it has a series of spaced balls I4 connected by wire or other suitable links IS. The bridge member may be covered between the eyecups by' a tube l6 of rubber or other suitable comparatively soft material as a cushion at-the bridge of the nose.

Adjusting movement of the bridge member in the passage H of an eyecup is controlled by a pin or detent IT in the bore [2 that is shiftable to and from intersecting lock position tween balls of the bridge. i

The pin or detent is of metal of spring properties, and it has such frictionally retentive contact with the wall of the bore that it is pre-- vented from dropping out and yet is susceptible of movement to and from lock engagement with the bridge member. i

A lock pin or detent of those characteristics is exemplified by Figs. 4 and 5.

As thus shown, it is a bifurcated or fork-like member with a shank consisting of two legs ll! of substantially equal length joined at a bridge engaging end IS. The detent is made so that it is of greater diameter at the free ends of the legs than the diameter of the bore l2 when it is outside thereof. Thus, when it is pushed into the bore, the legs have a tendency to expand and press against the bore wall and consequently have frictional action to retain the detent therein. The expansive urge of the detent legs, While suflicient to keep the detent from dropping out, still permits its release movement under action of the bridge abutments, and its lock movement in the opposite direction.

Detents of this character may be made advantageously from semi-circular or half-tube stock,

such as illustrated by Fig. 6, cut to proper lengths and bent midway of the ends to the form shown by Fig. 4. It has been found that stock arcuate in cross section and of thinner material gives a stronger and more efficient detent than flat stock which has to be thicker to afford effective expansive urge of the detent legs. Consequently, use of arcuate stock results in saving of metal.

The parts of the lock are so coordinated that, when the ring 9 is turned tight onto the eyecup to hold a lens 8 firmly against the front edge of the cup, the lens bears against the outer end of the detent l1 and holds its inner end locked with the bridge member. That member then cannot move in either direction in. the passage II. This is the normal position.

When it is desired to change the length of the bridge member between two eyecups, the ring 9 is turned and loosened enough to permit the lens to move from the front edge of the eyecup the slight distance required to let the detent shift from lock position on the bridge member. Then the bridge length may be changed by moving the bridge in the passage ll.

When the lock pressure of the lens on the detent i released, the balls of the bridge member can push the detent outwardly while the member is pulled in either direction. The expansive urge of the detent, while sufiicient to prevent the, detent from dropping out when the lens is entirely removed, is not sufiicient to prevent its release movement by balls of the bridge member. When adjustment is made, the bridge is relocked by tightening the ring 9.

The formation and arrangement of the parts are such that it is not necessary to turn the lens holding ring entirely oil of the eyecup to permit the detent to release the bridge member for length adjustment. All that is required to permit the detent to unlock is to loosen the ring; and, thus, in unlocking the bridge member, the ring still retains the lens on the eyecup.

The lock controlling adjustment of the bridge member may be associated with both eyecups of goggles; or it may be associated with one of them, in which case the bridge member is connected to the other cup in any suitable manner, as shown, for example, on one of the cups of Fig. 1. v

I claim:

1. In an ophthalmic device comprising an eyecup having a wall containing a transverse passage therethrough and a bore intersecting said passage and extending therefrom to the front edge of the eyecup and a bridge member longitudinally movable in said passage, a bifurcated detent with legs having spring expansive urge freely movable longitudinally in frictionally retentive contact with the wall of said bore, said detent normally having look engagement at its leg-joining end with said bridge member and being movable therefrom by action of said member moving longitudinally in its passage, and releasable means to lock said detent.

2. In an ,ophthalmic device comprising an eyecup having a wall containing a transverse passage therethrough and a bore intersecting said passage and extending therefrom to the front edge of the eyecup and a bridge member of connected balls movable longitudinally in said passage, a bifurcated detent with legs having spring expansive urge freely movable longitudinally in frictionally retentive contact with the wall of said bore normally in lock engagement as its leg-joining end with said bridge member and being movable therefrom by bridge ball moving in said passage, and releasable means to lock said detent.

3. In an ophthalmic device comprising an eyecup having a wall containing a transverse passage therethrough and a bore intersecting said passage and extending therefrom to the front edge of the eyecup and a bridge member longitudinally movable in said passage, a bifurcated detent with leg of spring expansive urge freely movable in and having frictionally retentive contact with the wall of said bore, said detent being rounded at its leg-joining end and there normally in lock engagement with said bridge member and being shiftable therefrom by movement of the bridge longitudinally, and releasable means to lock said detent.

4. In an ophthalmic device, the combination of an eyecup having a wall containing a transverse passage therethrough and a bore of sub stantially uniform diameter substantially perpendicular to and intersecting said passage and extending therefrom to the front edge of the eyecup, a bridge member of connected spaced balls movable in said passage, a lens on the front edge of the eyecup covering the outer end of said bore, loosenable and removable means for holding said lens in place, and a bifurcated detent with legs having spring expansive urge freely movable longitudinally in frictionally retentive contact with the wall of said bore normally held with its leg-joining end in lock engagement with said bridge member by contact of said lens with its outer end and being movable from lock engagement byaction of said bridge member moving longitudinally in its passage when said holding means is loosened.

ROBERT MALCOM. 

